US petrol price fluctuations - Wikipedia
From 1998 to 2004, the price of gasoline fluctuated between $1 and $2 USD per U.S. gallon. After 2004, the price increased until the average gas price reached a high of $4.11 per U.S. gallon in mid-2008, but receded to approximately $2.60 per U.S. gallon by September 2009. More recently, the U.S. experienced an upswing in gas prices through 2011, and by 1 March 2012, the national average was $3.74 per gallon.
In the United States, most consumer goods bear pre-tax prices, but gasoline prices are posted with taxes included. Taxes are added by federal, state, and local governments. As of 2009, the federal tax is 18.4? per gallon for gasoline and 24.4? per gallon for diesel (excluding red diesel). Among states, the highest gasoline tax rates, including the federal taxes as of 2005, are New York (62.9?/gal), Hawaii (60.1?/gal), and California (60?/gal). However, many states' taxes are a percentage and thus vary in amount depending on the cost of the gasoline.
About 9% of all gasoline sold in the US in May 2009 was premium grade, according to the Energy Information Administration. Consumer Reports magazine says, "If (your owner?s manual) says to use regular fuel, do so?there?s no advantage to a higher grade." The Associated Press said premium gas?which is a higher octane and costs more per gallon than regular unleaded?should be used only if the manufacturer says it is "required". Cars with turbocharged engines and high compression ratios often specify premium gas because higher octane fuels reduce the incidence of "knock", or fuel pre-detonation. The price of gas varies during the summer and winter months.
How much do you pay for using a car?
The costs of car usage, which may include the cost of: acquiring the vehicle, repairs and auto maintenance, fuel, depreciation, driving time, parking fees, taxes, and insurance, are weighed against the cost of the alternatives, and the value of the benefits ? perceived and real ? of vehicle usage. The benefits may include on-demand transportation, mobility, independence and convenience. During the 1920s, cars had another benefit: "couples finally had a way to head off on unchaperoned dates, plus they had a private space to snuggle up close at the end of the night."
Similarly the costs to society of encompassing car use, which may include those of: maintaining roads, land use, air pollution, road congestion, public health, health care, and of disposing of the vehicle at the end of its life, can be balanced against the value of the benefits to society that car use generates. The societal benefits may include: economy benefits, such as job and wealth creation, of car production and maintenance, transportation provision, society wellbeing derived from leisure and travel opportunities, and revenue generation from the tax opportunities. The ability for humans to move flexibly from place to place has far-reaching implications for the nature of societies.
Oil from plants
Organic oils are produced in remarkable diversity by plants, animals, and other organisms through natural metabolic processes. Lipid is the scientific term for the fatty acids, steroids and similar chemicals often found in the oils produced by living things, while oil refers to an overall mixture of chemicals. Organic oils may also contain chemicals other than lipids, including proteins, waxes (class of compounds with oil-like properties that are solid at common temperatures) and alkaloids.
Lipids can be classified by the way that they are made by an organism, their chemical structure and their limited solubility in water compared to oils. They have a high carbon and hydrogen content and are considerably lacking in oxygen compared to other organic compounds and minerals; they tend to be relatively nonpolar molecules, but may include both polar and nonpolar regions as in the case of phospholipids and steroids.